TitleThe influence of family-correlated survival on N-b/N for progeny from integrated multi- and single-generation hatchery stocks of coho salmon (Oncorhynchus kisutch)
Publication TypeJournal Article
Year of Publication2007
AuthorsMoyer, GR, Blouin, M, Banks, MA
JournalCanadian Journal of Fisheries and Aquatic Sciences
Volume64
Pagination1258-1265
Type of ArticleJournal Article
ISSN0706-652X
Abstract

There exist surprisingly few data on the final variance and mean of family sizes for hatchery-born fish at the adult stage. Thus, it is difficult to predict, for a conservation hatchery operation that minimizes the variance in progeny number, how much lower the true effective population size (N-e) of a cohort of hatchery-born adults will be than N-e predicted simply by the number of parents that produced them. We used parentage analysis to estimate the survival and N-e for two integrated stocks of hatchery coho salmon (Oncorhynchus kisutch). One hatchery is a multigeneration stock obtained by spawning 70% hatchery with 30% naturally reproducing fish, whereas the second is a single-generation stock derived from naturally reproducing coho. There was no significant difference in average overall survival between stocks, but observed N-e was significantly less than expected for each stock. Family-correlated survival contributed to roughly a 20% reduction in N-e over the freshwater and marine life stages. This reduction is similar to previous estimates and suggests a value that can be used when estimating the effective number of hatchery parents in applications of the Ryman-Laikre formula (at least for programs such as ours that attempt to equalize sex ratios and family sizes).

URL<Go to ISI>://WOS:000249973700009
DOI10.1139/f07-099